Friday, July 17, 2009

Common Garden Insects and Solutions by Mary Small

Small, soft-bodied pear-shaped. Usually congregate on tender tissue. May cause leaf and stem distortion.
Wait for ladybug, lacewing and syrphid fly predators; hose off with water; apply insecticidal soap or horticultural oils. Follow label directions.

Small insects that jump when disturbed. Make shothole shaped holes in leaves of cabbage, tomato, many weeds and flowering plants. Cover vegetable crops with floating row covers during establishment period. Apply diatomaceous earth or neem insecticides or horticultural oils or bifenthrin or permethrin. Follow label directions.

Tiny spider-like insect relatives. Leaves have pale-colored flecks. Leaves may yellow, bronze and drop. Webbing may be visible. Keep plants adequately watered to deter mites. (They are attracted to and proliferate on drought-stressed plants.) Dislodge with spray of water. Apply insecticidal soaps or horticultural oils. Follow label directions.

Small ¼ inch brown or gray oystershell-shaped insects. Heavy infestations kill branches, cause wilting or yellowing. Gently scrub off overwintering adults on woody plants during dormant period. Apply horticultural oils, insecticidal soaps or contact sprays during the scale hatch period (late May-early June). Follow label directions.

INSECT:LILAC-ASH BORER Cream-colored grubs tunnel under bark, weaken tree or shrub; interfere with sap flow. Look for round exit holes, branch dieback. Attracted to stressed plants, so keep plants healthy. Avoid pruning when adults fly, April through June. Apply permethrin or carbaryl on trunks. During adult flight period. Follow label directions.

Mary Small
Extension Agent, Urban IPM
Colorado State University Extension
Jefferson County